/*
 * JaLingo, http://jalingo.sourceforge.net/
 *
 * Copyright (c) 2002-2006 Oleksandr Shyshko
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

package ja.centre.util.search;

public class TextSearcher {
    private TextSearcher() {
    }

    public static int indexOf( boolean forwardDirection, String text, String subject, int searchFrom, boolean caseSensetive, boolean wholeWordsOnly ) {
        if ( !caseSensetive ) {
            text = text.toLowerCase();
            subject = subject.toLowerCase();
        }

        int index = forwardDirection
                ? text.indexOf( subject, searchFrom )
                : text.lastIndexOf( subject, searchFrom );

        if ( wholeWordsOnly && index != -1 ) {
            if ( index > 0 && !isWholeWordSepararator( text, index - 1 ) ) {
                //System.out.println( "# left: " + text + ", " + index );
                index = -1;
            } else if ( index + subject.length() < text.length()
                    && !isWholeWordSepararator( text, index + subject.length() ) ) {
                index = -1;
                //System.out.println( "# right: " + text + ", " + index );
            }
        }

        return index;
    }

    // NOTE: everything is a separator but: letter, digit and underscore
    static boolean isWholeWordSepararator( String text, int index ) {
        char c = text.charAt( index );
        return !Character.isLetter( c ) && !Character.isDigit( c ) && c != '_';
    }
}
